Advancing Conservative Treatment of Knee Osteoarthritis: 3D-Printed Shoe Soles for Passive Toe-Out Gait Modification.
Publisher DOI
PubMed ID
42332343
Abstract
Introduction
To evaluate whether a 3D-printed shoe sole can passively replicate toe-out gait biomechanics and reduce the knee adduction moment (KAM) and knee adduction angular impulse (KAAI), addressing limitations of traditional gait retraining.Methods
Custom shoe soles were 3D-printed using gyroid infill structures to create a rotational hind-sole and a variable stiffness fore-sole ('RVS' shoes). Twenty-one healthy adults completed three baseline gait trials in control shoes, followed by randomised biofeedback-based gait retraining at toe-out angles of 5°, 10° and 15°. After each retraining session, motion capture was used during overground walking. Participants then walked wearing RVS shoes for three trials. Gait biomechanics were analysed using repeated measures ANOVA and multiple linear regression.Results
Compared to baseline, KAM's second peak was significantly reduced after toe-out retraining: 5° (13.6%, p = 0.002), 10° (20.2%, p < 0.001) and 15° (31.7%, p < 0.001). RVS shoes alone reduced it by 16.3% (p < 0.001), and KAAI by 8.6% (p < 0.001)-a reduction not achieved by retraining. Regression analysis showed that changes in KAM were strongly predicted (95%) by knee centre-of-pressure offset and mediolateral ground reaction force.Conclusion
3D-printed RVS shoes passively replicated or exceeded the biomechanical effects of active toe-out gait retraining, offering a promising, low-effort intervention for managing knee osteoarthritis.
To evaluate whether a 3D-printed shoe sole can passively replicate toe-out gait biomechanics and reduce the knee adduction moment (KAM) and knee adduction angular impulse (KAAI), addressing limitations of traditional gait retraining.Methods
Custom shoe soles were 3D-printed using gyroid infill structures to create a rotational hind-sole and a variable stiffness fore-sole ('RVS' shoes). Twenty-one healthy adults completed three baseline gait trials in control shoes, followed by randomised biofeedback-based gait retraining at toe-out angles of 5°, 10° and 15°. After each retraining session, motion capture was used during overground walking. Participants then walked wearing RVS shoes for three trials. Gait biomechanics were analysed using repeated measures ANOVA and multiple linear regression.Results
Compared to baseline, KAM's second peak was significantly reduced after toe-out retraining: 5° (13.6%, p = 0.002), 10° (20.2%, p < 0.001) and 15° (31.7%, p < 0.001). RVS shoes alone reduced it by 16.3% (p < 0.001), and KAAI by 8.6% (p < 0.001)-a reduction not achieved by retraining. Regression analysis showed that changes in KAM were strongly predicted (95%) by knee centre-of-pressure offset and mediolateral ground reaction force.Conclusion
3D-printed RVS shoes passively replicated or exceeded the biomechanical effects of active toe-out gait retraining, offering a promising, low-effort intervention for managing knee osteoarthritis.
Date Issued
2026-06
Publication Type
Article
Subject(s)
Subjects
3D‐printed shoe soles
•
foot orthosis
•
gait modification
•
joint kinetics
•
knee osteoarthritis
Language(s)
en
Author(s)
Jiang, Ziang | |
Studer, Paciane Bo | |
Zäh, Matthias | |
Kryenbühl, Christian | |
Taylor, William R | |
Zhang, Qiang |
Journal
Journal of Foot and Ankle Research
Publisher
Wiley
ISSN
1757-1146
Funding(s)
Access(Rights)
open.access